Rotary turbine type fluid coupling



A. M. LEXANDRESU ROTARY TURBINE TYPE FLUID COUPLING oct. l; 1955 9 Sheets-Sheet l Filed Feb. 18, 1952 Oct. 18, 1955 A. M. ALExANDRr-:SCU 2,720,952

ROTARY TURBINE TYPE FLUID COUPLING Filed Feb. 18, 1952 9 Sheets-Sheet 2 ggf/MM 0 O O Il.

Oct. 18, 1955 A. M. ALEXANDRESCU ROTARY TURBINE TYPE FLUID COUPLING 9 Sheets-Sheet 3 Filed Feb. 18, 1952 INVENTOR. lMA/DflQA/ZAYANDRESCU f. n x

9 Sheets-Sheet 4 INVENTOR.

mmf/aff M flair/:#0276560 BY Oct. 18, 1955 A. M. ALExANDREscU ROTARY TURBINE TYPE FLUID COUPLING Filed Feb. 1a, 1952 x x A I Oct. 18, 1955 A. M. ALEXANDRESCU ROTARY TURBINE TYPE FLUID COUPLING 9 Sheets-Sheet 5 Filed Feb. 18, 1952 Oct. 18, 1955 A. M. ALEXANDRESCU ROTARY TURBINE.' TYPE FLUID COUPLING 9 Sheets-Sheet 6 Filed Feb. 18, 1952 IIS 1N V EN TOR. MEM/VDE? M ZEM/VDESCU BY Oct. 18, 1955 A. M. ALExANDRl-:scu 2,720,952

ROTARY TURBINE TYPE FLUID COUPLING Filed Feb. 18, 1952 9 Sheets-Sheet 7 l .59 2/7 2/6 v I INVENTOR. P 4am/WM M. Aww/026560 @7a2 2 Mah/EME;

Oct. 18, 1955 A. M. ALEXANDRE-SCU ROTARY TURBINE TYPE FLUID COUFLING 9 Sheets-Sheet 8 Filed Feb. 18, 1952 #17de/var Oct. 18, 1955 A. M. ALExANDREscU ROTARY TURBINE TYPE FLUID COUPLING 9 Sheets-Sheet 9 Filed Feb. 18, 1952 O 86) LL INVENTOR. Azam/ausw @g/2f a/C United States Parent Gtice 2,720,952 Patented Oct. 18, 1955 ROTARY TURBINE TYPE FLUID COUPLING Alexander M. Alexandrescu, Cleveland, Ohio Application February 18, 1952, Serial No. 272,030 18 Claims. (Cl. 192-3.2)

The present invention relates generally to nnprovements in automatic iluid driving control systems for automotive vehicles and the like, and more particularly to iluid coupling devices such as the mechanisms disclosed in my United States Patent No. 2,569,087, Rotary Turbine Type Fluid Coupling, issued September 25, 1951, and my co-pending United States patent applications, Serial No. 122,236, tiled October 19, 1949, now abandoned, Fluid Coupling with Cupped Blades, Serial No. 136,896, led January 5, 1950, now abandoned, for Fluid Coupling with Advanced Blades, and Serial No. D. 16,585, tiled September 8, 1951, now abandoned, for Automatic Rotary Fluid Projecting Device.

An object of the present invention is the provision of a lluid coupling device having over the full range of operation improved torque transmission characteristics with respect to the torque transmission e'iciency and to the smoothness of torque communication.

A further object is the provision of an improved fluid coupling which is simple in construction, low cost in the materials and operations of manufacture and of compact, rugged structure.

Further objects and advantages of the invention will appear in the following description and the drawings of this invention wherein` Fig. 1 is a longitudinal vertical section of this invention taken through the axis of rotation along the lines 1-1 of Fig. 2 showing a two-stage lluid coupling unit, with an associated automatic driving control unit and a hydraulically actuated safety clutch;

Fig. 2 is a vertical section taken through the fluid coupling unit transverse to the axis of rotation along the line 2 2 of Fig. l and showing the form of the uid impeller and turbine blades;

Fig. 3 is a vertical cross sectional View taken through the fluid coupling device transverse to the axis at the same position as Fig. 2 but looking to the rear of the device;

Fig. 4 is a view from the front of the second stage turbine wheel, certain parts being broken away t show the form of the turbine buckets and radial fluid return channels of the turbine wheel;

Fig. 5 is a fragmentary sectional view of the fluid coupling unit taken circumferentially at the line 5-5 in Fig. 1 to show the form and disposition of the inner ends of the fluid impeller blades;

Fig. 6 is a fragmentary sectional View of the fluid coupling unit taken circumferentially at 6 6 in Fig. 1 to show the shape of the iiuid impeller blades and nid return channels of the turbine blades at a locus radially outward from that of Fig. 5;

Fig. 7 is a fragmentary sectional View taken along the staggered section line 7-7 of Fig. 4 to show the form of the outer end structure of the turbine blades;

Fig. 8 is a fragmentary sectional view taken similarly to Fig. 1 showing a single stage tluid coupling unit having impeller and turbine blades similar to those of Figs. 1-7;

Fig. 9 is a fragmentary sectional view taken similarly to Fig. 1 but showing a second form of impeller and turbine blades arranged in dual parallel acting sets as a single stage drive;

Fig. 10 is similar to Fig. 8 but has a third modication of the blade forms;

Fig. 11, similar to Fig. 9 discloses a single stage fluid coupling with a form of turbine blades generally similar to those of Fig. 10, but arranged in double sets;

Fig. 12 is a fragmentary section taken along the line 12 12 of Fig. 11;

Fig. 13 is a fragmentary longitudinal section of a single stage tluid coupling unit having a fourth form of blades arranged in parallel sets, the view being taken vertically through the axis of rotation;

Fig. 14 is a fragmentary sectional view taken circumferentially along the line 14-14 of Fig. 13;

Fig. 15 is a transverse section of Fig. 1 taken along the line 15-15 of Fig. 1 to show a vertical section of the hydraulic fluid pressure pump;

Fig. 16 is a fragmentary section taken through the pump and automatic driving control unit along the line 1616 in Fig. 15;

Fig. 17 is a transverse section of the automatic drive control unit, taken along the line 17-17 in Figs. 1 or 16 showing the control valve solenoid in unenergized position and the corresponding position of the automatic driving control valve;

Fig. 18 is a detail of Fig. 17 showing the arrangement of the automatic driving control valve and an associated relief valve in the pump base;

Fig. 19 is a fragmentary section taken horizontally along 19-19 in Fig. 18 through the automatic driving control valve and the adjacent relief valve in the bearing pillow block;

Fig. 20 is a vertical transverse section taken between the pump and automatic driving control unit along line 21)*20 in Fig. 16 to show the structure of the uid drive pressure control valve and nid feed channels from the pump, the valve being closed;

Fig. 21 is similar to Fig. 2O but shows the valve open;

Fig. 22 is similar to Fig. 17 showing the control valve solenoid energized and the corresponding position of the automatic driving control valve;

Fig. 23 is a detail of Fig. 22;

Fig. 24 is a fragmentary horizontal section corresponding to Fig. 19 but showing the automatic driving control valve position of Fig. 22; and

Fig. 25 is an electrical control circuit for operating the automatic driving control valve.

Though the present invention is adapted to other environments, in the drawings and this specification, for the sake of convenience, it is shown and described as applied to an automobile. Thus in Fig. l, A represents the rear part of an auto engine block, B the crankshaft of the engine and C the fly-wheel provided with the usual starter ring gear. A housing D attached to the rear of the engine block encloses a uid coupling unit E, a uid pump F, a hydraulically actuated clutch G and an automatic driving control unit H for which a solenoidal actuating unit I is mounted eXteriorly of the housing. The housing D comprises an upper portion with a transverse web 51, and a lower iluid pan 52 gasketed and bolted thereto to serve as a sump for oil or other suitable hydraulic fluid. ln the housing D suitable filling, inspection and drainage plugs 53, 54 and 55 are provided.

The web 51 and pillow block 56, mounting the split shell type bearing 57, and the base of pump F are held together by studs 58 and nuts 59. The rear end of the crankshaft B is provided with a ily-wheel mounting flange 61 and a reduced portion 62 extended through the fly-wheel and bored coaxially to receive a sleeve or pilot bearing 63 having interior longitudinal lubricating channels. The main shaft 65, with the reduced portions at the forward end and toward the rear journalled in bearings 63 and 57 respectively, mounts the outer member or casing of the clutch G at its rear end beyond the web 51 as is hereinafter described. The uid coupling unit E comprises a two stage series drive system, each stage including ya Vset of iiuid impeller and 'turbine blades, with the turbine of the first stage driving the impeller blades of the second. As shown in Fig. l, the casing of the unitvE comprises two halves bolted together along flanges, with a gasketinterposed to form a liquid-tight joint. The forward half 67 of the casing, to the conically dished end wall 109 of which the fluid impeller blades 68 of the first stage 'are brazed, welded or riveted, is secured to 'the y-wheel by cap screws-69 ypassed through the Vfly-Wheel into the crankshaft Vend flange '6'1 and by cap screws 70 threaded Vinto the y-wheel. The rear half 72 of the casing, provided with a filling plug 73 alignable with the housing plug 53 for initially filling the casing, is rotatably mounted'on the main shaft 65'through the medium of the bushing 74 having a flange portion 75 to which the casing half 'is bolted and a worm 76 cut thereon -for 4driving the pump F as hereinafter described. On the sleeve bearing 77, pressed -into bushing 74, there is an end ange 78 extended into 'the casing, and from this ange lubricating .grooves are cut partly d own the length of the bearing surface.' To a iange y'79 of the mainshaft 65 is bolted 'the turbine wheel 80 carrying turbine blades 81 -of the vsecond stage. -Between the uid impeller wheel of the first stage and the Aturbine wheel 80 of the second stage -there is interposed the first stage turbine wheel vr82 Vand second stage uid impeller wheel 83 commonly secured back-to-back to the fiange 84 on the sleeve shaft 85 rotatably mounted onthe main shaft. Between the flange 79 and the end flange 78 on the bearing Y77 Vthere is 'provided a thrust bearing and spacer ring 86 radially grooved on each bearing face for lubrication purposes.

ln the sleeve shaft 85, lfrom an innerV circumferential groov'em88 lubrication vgrooves -are cut lengthwise to the ends ofthe sleeve shaft -and radial apertures V89 vopen from groove 88 through the shaft wall. A central channel 91, bored in the ymain Vshaft `from the 'forwarde'nd and extending .part-way into the length of the reduced portion withinbearing 57, opens through the radial'apertures y92 and 93 respectivelyY to the sleeve shaft groove 88 and to the circumferential groove 94 in the bearing surface of bearing 57. A channel 95 cut in web 51 and pillow block 56 communicates through bearing apertures 96 Hwith groove 94. These channels associated with groove 94 are best seen in Fig. 17. ln a similar manner as clearly appears from aFig. a second circumferential channel-97 in the web and pillow block about the bushing 57 opens through theradial bearing apertures 99 to a circumferential groove 100 in bearing 57 and thence through the radial channels 101 in the main shaft t`o a sechd central bore 102 opening into the clutch sleeve o'rpil'o't'bearing recess at the clutch end'of the main shaft 65.l By means of these several shaft and bearing passagesl `liuid Vsupplied under pressure Vfrom pump F to the' channels 95 and 97, in a manner hereinafter described, may be delivered -to the uid drive unit, to the clutch mechanism, and to the bearings for forced lubrication. j

'As ythe uid impeller blades and turbine bladesof one stage are identical to those of the other they are desig- Y nated by like numerals and will be described by reference -to either stage as shown in Figs. 1-7. The 'uid impeller blades 68 in this form of the invention have outer-edges and radialfedges at right angles toe'ach other and in close Working proximity to ythe correspondingly shaped adjacent edges of the V'turbine blades :81 as may be seen in Fig. 1, the Yblades projecting axially, i. e., in a direction substantially parallel to the vaxis of rotation, from the surfaces Aon which mounted. Each impeller Spot welding, brazing or blade 68 is secured, as by spot welding, along its flange to a disk portion 109 of the iiuid impeller, the end wall of the casing member 67 providing the disk in the first stage. The body of each blade 68, as appears in Figs. 1, 2, 3 and 5, comprises a substantially radially disposed section 111 merging into an outer portion 112 curved forwardly to terminate in the outer free edge thereof (i. e. in the direction of rotation), an inner edge provided with a lip 113 folded forwardly about 45, a laterally projecting fluid shifting vane portion 114 bent forwardly at k45" to the blade body and extending under the bottom lof the uid return 124 of the turbine blades, and a forwardly foldedflateral edge 115 radially outward of the vane portion 114. The vane portion 114 is cupped by folding its edges forwardly, thus providing a continuous edge fold along the lateral free edge of the blade body around the vane portion and across the inner edge 113, which serves to reinforce each blade so that relatively thin sheet metal maybe used for the blade stock. Important operational functions of the edge folds will be later described. I

Each turbine wheel 80, 82 comprises a disk 118 with a circumferential ange 1'19, a plurality of blades 81 preferably exceeding slightly by an even number the blades of the corresponding impeller, lto effect a smoother power transmission, and a fiat ring extending inwardly of the end of flange 119 to close the end space between adjacent buckets. The form and disposition of the turbine blades can be clearly seen from Figs. 1, 4, 6 and 7. Each turbine blade comprises arearwardly open curved bucket 121 secured by end ange 122 and longitudinal flange 123 respectively to ring 120 and circumferential flange 119, and a radially extended fluid return portion 124 secured to Vdisk 118 by flange 125, the outer end of'thevuid return opening into the end of the bucket. The length of the bucket portion of the turbine blades is somewhat greater than the breadth of the impeller blades, so vthat the ring 120 lies outside the impeller blades. Hence Athe end wall 109 is recessed annularly'to accommodate and clear the rim of theV turbine wheel. Similarly to the impeller blades, each fiuid return portion has a lateral or radial edge 126 folded at 90 to the body of the blade, but opposite to the direction of rotation, to form a radial 'continuation of the rear edge of bucket 121,-so that corresponding edge 'portions on impeller and turbine blades are folded in mutually opposite directions. p Y riveting may of course be used to affix the turbine blades. As in the case of the impeller blades, the several flange, edge fold and curved formations of the-turbine blades confer structural strength 'permitting manufacture from lightvsheet stock by stamping, pressing or drawing operations. Since thecasing members 67-7-2 Vand the impeller and turbine wheel disks may likewise be formed Yfrom sheet metal of fsuitable gage by stamping, vpressing or drawing operations, the structure described is adapted to low cost mass production -of Va simple, compact, sturdy and eiiicient uid coupling unit.

By the blade structures described, achannel for radial outward ow of hydraulic fluid is provided between the impeller blades 68 directing the tiuid forwardly i'nto lthe turbine buckets 1-21 with va slight lateral component toward the return channel due tothe dished form of'th'e disks 109. At idling speed the forward impeller blade curvature isetfective to minimize drag between impeller and turbine elements. -Between the blades 81 in turn'there is a channel for radialreturn ow. Also bythe provision of the folded lateral edge 115 on the impeller blade,`uid tending vto escape in an axial direction from between adjaeentturbin'e blades -s intercepted by a passing irnpeller blade. The "slanted fluid shifting vane-114 at the bottomof the impeller blade picks up 'iiuid leaving the bottom iof turbine 'return channel 124 for a quickreturn intothe'impeller system, while'with the lateral edge 126 partially 'enclosing the radial `space between the turbine blades, uid projected into the buckets is returned and direced more effectively against the face of vane portion 114. These several structural features of the blades contribute to more effective uid coupling at high speeds, and a smooth torque application at all times.

Due to the double fluid coupling interposed between engine and main shaft 65, very smooth pickup is obtained in a vehicle provided with the two stage coupling unit of Figs. 1-7 while drag between driving and driven elements is minimized. Hence this type of unit is particularly useful in conjunction with high speed engines.

Other blade forms and arrangements of a single stage type are shown in Figs. 8-14 wherein elements similar to those of Figs. l-7 are designated by like numerals. Fig. 8 discloses a form of uid drive unit with blade forms similar to those of Figs. 1-7 wherein a single stage drive is used comprising but one impeller and turbine wheel, each with a single set of blades. As the sleeve shaft 85, shown in Figs. 1 and 2, and the structures auxiliary thereto are unnecessary and hence omitted, the casing and shaft are shortened and modified accordingly. Such a unit has high coupling eiciency but is adapted rather to use with slower type engines.

In Fig. 9 there is disclosed a single stage unit wherein impeller blades and turbine blades of individual form generally similar to those of Figs. l and 2 are used. However, two sets of impeller blades 68 are arranged on the end disks 109 of the two halves of the casing, while the two sets of turbine blades 81 are arranged on flanged rings 118 secured to opposite sides of a heavy disk 80a bolted to ange 79 on the main shaft for rotation between the two sets of impeller blades. The anged rings 118 are shaped similarly to the blade mounting portion of turbine disks 118 of Figs. 1 8. The main shaft 65 is changed in form from that of Figs. l and 2 by the omission of structural features rendered unnecessary by the lack of the sleeve shaft, and by the addition of the thrust ange 139 bearing against the end ange 78 of bearing 77. ln this case the lateral folded edges of the turbine and impeller blades 126 and 115 are inclined relative to the axis of rotation, whereby the outward liow in the impeller blades is directed into the turbine buckets with a lateral component somewhat greater than in the previous forms.

Since here there are in effect two duid couplings acting in parallel between engine and shaft 65, this arrangement is adapted to heavy duty service where large torque demands are encountered, especially with slow speed engines such as diesels. By the opposed paired disposition of the turbine blade sets, reactive forces developed on opposite sides of the turbine wheel unit counterbalance each other to prevent undue axial stresses and attendant wear. Similarly the fluid forces acting on the casing are balanced.

In the coupling units of Figs. 10-14, the impeller and turbine blade forms, as compared to those previously described, develop a greater lateral component in the projected uid iow, due to the fact that in addition to the forward curvature shown in Figs. 1 9, the outer ends of the impeller blades have a laterally directed curvature to direct the ow into the turbine buckets at 45 to plane of rotation. Such blade forms develop a smoother vehicle pick up than would normally be obtained by the blade forms of Figs, 1-9 in a single stage coupling when used with high"speed engines. Y Because of the lateral curvature of thefimpeller blades, they are secured to an annular disk theouter portion of which is curved correspondingly, the diskinitlurnbeing' bolted to theicasing end wall.

In the singlestage coupling .show'nin Fig.' l0, the dis position of the uid return portion 124 of the turbine blades and the uid shifting vane portion 114 on the impeller blades is similar to those of Figs. 1-8. However, the outer ends of the impeller blades in addition to being curved forwardly in the direction of rotation, are shaped to deect the ow from a generally radial direction into the turbine bucket 121 at an angle of about 45 to the axis of rotation and the impeller blades are mounted on CII a correspondingly curved ring 109e bolted to the casing end wall. The turbine wheel disk 118 is joined to circumferential ange 119 by a corner 132 of large radius as compared to previous forms, and the turbine blades are correspondingly modified at the bucket portion 123 which extends obliquely to the axis of rotation across the corner 132 from flange 119 to uid return 125 at an angle of 45 to ange 119 to accommodate the shape of the impeller blades.

In Fig. 1l is shown a single stage drive provided with a dual system of turbine and impeller blades mounted similarly to Fig. 9, the form of the individual blades, however, being substantially that of Fig. 10. The disposition and form of the fiuid shifting vane portions 114 and turine blade Huid return portions is quite similar to that of the form of Figs. 1-7 as shown by the fragmentary circumferential section in Fig. 12. The blade form of this device suits it to use with high speed engines, while the dual arrangement in single stage coupling, with axial reaction force components counterbalanced as in the structure of Fig. 9, adapts it to heavy duty service.

1n Fig. 13 still another form of blades is shown arranged in a dual system of turbine and impeller blades mounted in a single stage drive for heavy duty service as in Figs. 9 and ll. The outer ends of the impeller blades 68 in this case deflect the outward flow of fluid from a radial direction at an angle to the axis into the turbine buckets 123 in a manner similar to the blades of Figs. 10 and 11. The adjacent surfaces of the turbine and impeller blades between the fluid shifting vane portions 114 and the outer ends of the impeller blades are complementarily shaped to project inwardly with respect to each other by virtue of the sinuous edge formations 133, 134. These formations 13S-134, serving as minor shifting vane portions intercepting iiuid in the interblade channels, also induce additional fluid reaction forces which results in a more eiiicieut duid coupling particularly at low relative speeds between impeller and turbine wheels, or under heavy loads. The blades here are folded on edges corresponding to the folded edges of the previous blade forms. Fig. 14, a circumferential section of Fig. 13, clearly shows the curved form of the iiuid shifting vane portions. Here the impeller blade mounting ring 109a is flanged at 135 partway about the inner ends of the blades as well as the outer ends, and the radial attachment ange 110 of each impeller blade is continued by the angularly disposed ange portion l10n to provide additional support for the inner end of the impeller blade.

The structure of hydraulic fluid tains hydraulic uid under a few pounds pressure in the fluid coupling unit in addition to other functions, is best seen in Figs. 15 and 16, the latter ligure also showing clearly the relation of pump to automatic driving control unit H. The pillow block 56, which also forms part of the automatic drivina control and serves to mount the pump structure, projects beyond the transverse web 56 toward the Huid drive unit. The pump base is sealed to the bottom of the pillow block 56 by a gasket 151 and held by nuts 152 on studs 153, with the pump extending downwardly toward the bottom of the fluid pan with its lower end below the normal sump liquid level. A gear pump mechanism, comprising the gear 154 revolvable on the stub shaft 155 and gear 156 cut on the lower end of pump drive shaft 157, is enclosed in a cavity in-the lower end pump F, which mainof the pump body by pump cover 158 through which intake port 159 opens to the sump. The pump driv'eislgni,ft` 157, joug-nailed near its lowerI end in the pump bodyaiid near the upper end in the pillow block, is driven by the worm 76 on bushing 74 through gear 161 keyed to the upper end of the pump shaft and held thereon by means of nut 162. :1"

Fluid taken in to the gear pump through the intake port 159 in the pump cover is delivered through outlet port 164 to the fluid reservoir cavity surrounding the pump shaft. A pressure relief provided by the longitudinal i valvel 167 mounted in the lateral projection 168 on the pumpk casing and openingY to the reservoir by the passage allows the, pump. tol discharge fluid to the fluid pan through the, vents 170 when the pressure exceeds, say, 25f30 p. s. i.- A second passage 171 in projection 168 opening to the pump reservoir is vconnected by conduit 172 to the fluid channel 173 in the transverse web as shown in Fig, 2l for purposes hereinafter described. Hydraulic uid is delivered from the top of the huid reservoir 165Y through a distributing channel 175 toV the bottom of automatic fluid driving, control valvermember V, and through lateral channel 176 opening upward through the channel 177, to thecircumferential groove 95 about the main shaft btaug' for Supplying4 fluid to the fluid drive unit. Ask shown'in Figs. 20 and 21, in the channel 177 there is a springV biased pressure regulating valve 178 limit-ing the pressure inn uid drive unit E and retaining iiuid in the passageways and fluid coupling unit. The spring bias of valve 1.7 8 is chosen (relative to the pressure limit of pump relief valve 167) to limit the pressure in the huid coupling unit to about p. s. i. when the pump is operating. The portionu of the pillow block 56 projecting beyond web 51 is provided with a semi-circular trough 180 extending partway around andunderneath the worm 76 on the bushing 77; The worm 76 dips into a body of hydraulic iiuid which leaks between shaft 65 and bearings 57 and 77 or between the pumpv shaft and casing into trough 180, thereby providing continuous lubrication for the pump e shaft gearing.

The automatic driving control unit H, illustrated in Figs. 16724, comprises the cylindrical valve member V rotatable in a'valve sleeve 182 held in set position in the pillow block 56 by the set screw 181 and the actuating unit I includes a solenoidai powered mechanism for rotating the valve shaft 1 84 journalled in the web 56 and having its lower end provided with a tongue engaged in a transverse slot Vof the valve member V.V A. pin ory set screw 181 engaging, an arcuate slot in valve member V, retains the valve member in axial position. The solenoid actuating unit J situated on top of the housing D and enclosed bythe casing 1,85 comprises the solenoid 186, an armature 187 biased, by spring 188 away from the solenoid and provided with a yoke .1S-9 sliding in guide 190, disposed about the flanged head 191 of the actuating shaft and having a pin 192 engaging a radial slot 19,3 inthe flange of the shaft head.Y Thusas the solenoid is energized, the armature draws `the yoke inwardly against the bias of the spring, thereby rotating the valve member from one position to another. To position the valveA actuating shaft more exactly in the two extreme positions, a spring biased detent ball 195, engageable with two detent formations on thel under-side of the shaft head, is provided in the housing. As shown` in Figs. 17, 18 and 19 wherein the solenoid andA valve member Vare in off position, the channel 175 from the pump reservoir opens to a central bore 200 extendingpartway up the valve member V. Two longitudinally extending slots 201, 202 are cut into the valve member, to meet the central bore 200 and are alignable respectively with the slots 203, 204 through the sleeve 182. The valvey member V is also provided at the height of sleeve slots 203, 206 with a circumferentially extended groove 297; of peripheral length suflicient to span the slots 203, 20.6` when rotated to. on position by the energized solenoid, From sleeve slot 204 a passage 208 runs through the pillow block to relief valve 209 in the pump base 150 which discharges through vent 210 to the fluid pan. Sleeve slot 206 likewise opens through a relief valve 212 in pillow block 56 in channel 213 discharging through the opening 214 to the fluid pan. Valves 209 and 212 are both lightly loaded4 to open readily under pressure but to close oi the exhaust lines against static drainage and entrance of air. From sleeve slot 203 a passage 215 runs to the circumferf ential groove 97 about bearing 57 and to a channel 216 through the pillow. bloclr` and pumpVV casing connected by theV conduit 217 to the passageA 128 opening laterally through the web member 53. I

ThusV with the valve member V in the position shown in Figs. 17 to 19, for the unenergized condition of the solenoid (when the engine is idling), huid delivered by the.

haust from the circumferential groove 97 and passage 216 v through channel 215 and slot 203 which is open (Fig. 1 9) through valve member groove 2,07 to the light relief valve 212. Valve 212 readily opens for discharge of uid through vent 214, but closes at near zero pressure to ex clude air from thepassages.

When the solenoid is in energized position as shown in Figs. 22-24, the valve member is rotated to a posi. tion such that the longitudinal slot 201 in the valve member is brought into alignment with theA channel 203 through the valve sleeve to allow delivery of lluid under pressure from the pump through the central bore 200I through channel 215 to the circumferential channel 97 for actuation of the clutch and to passage 216 for actuating a control valve of a hydraulic shifting, mechanisms With the valve in this position, the passages to the relief valves 209 and 212 are closed.

The hydraulic clutch unit G shown in Fig. 1 includes A a casing comprised of a cylindrical half 230, the hubV portion 231 of which is secured to the end of the main shaft 6 5. by the set screws 232 projecting into radial apertures of the shaft, and a conical portion 2,33l bolted to the cylindrical portion along the circumferential anges. A clutch output shaft 235, 'having a reduced end 236 journalled in the sleeve bearing 237 in the end of the main shaft, carries a conical inner clutch member 238 splined thereto to allow axial movement for engaging the conical surface of the casing. The inner member 238V is biased toward disengaged position by the helical compression spring 239 interposed between the end of the inner clutch member and the thrust washer 240-seated on a shaft 235. The outer end of shaft 235 is journalledV casing and' provided with stop rings. or flanges 246 to. space the piston from the end wall when in the extremeI position. The central bore 247 in the clutchshaft which opens to the bottomof. the bearing recess andso to. bore 102' of the main shaft, is provided with radial apertures 248 opening into the space between the annular piston and the casing` Thus fluid supplied under pressure to. the circumferential groove 97 about the bearing 57V upon actuation of valve V by the solenoid passes through thev channelsV previously described in bearing 57, main` shaft. and the clutch shaft 235- into thek space. behind the piston 242 to move the inner clutchv member 238 axially into engagement with the conical portion ofthe clutch casing. When the solenoid is die-energized, thus setting` valve V to allow fluid to exhaust from groove 97,` the. clutch can move into disengaged position under bias of spring 239, while fluid from the automatic. fluid shift cylinders can return through 1721 to the pumpL reservoir, Y

since the pump is running at idling speed,l to,Y exhaust through channel 176 to valve 209,. I Y

In Fig. 25 thereY is shown thewiring diagram forani electrical circuit controlling the solenoid 186 of the hywhen the lever is moved from a neutral to a forward or reverse position, and the switch 252 is mechanically linked to the engine acceleraor pedal to close upon acceleration, so that the solenoid is energized only when the shift control lever is set for forward or reverse operation and the accelerator is depressed. However, the switch 253 is manually operable in case of emergency (e. g. failure of switch 251 or 252) or during descent of hills, or other occasion requiring engine braking, to energize the solenoid and so to set the entire mechanism in driving relation to utilize the engine braking action.

When the engine is to be started, the shift lever is set to a neutral position, thereby opening switch 251 so that the solenoid remains unenergized and hence the valve V remains in closed position. Thus the clutch will remain disengaged during the starting operation. After the engine has been started, the clutch remains disengaged until such time as both switches 251 and 252 are closed by setting the shifting control lever to an operating position and by depression of the accelerator pedal. When the shift lever is set to a desired operating position, thereby closing switch 251 and the accelerator is depressed, closing switch 252, the solenoid is energized to set the valve member V to its open position as shown in Figs. 22-24. With the acceleration of the engine and the y-wheel with attached impeller blades, uid is centlifugally projected into the turbine buckets developing torque which is applied to the main shaft. At the same time fluid supplied under pressure by the pump builds up pressure in the fluid drive unit to increase the efliciency of coupling and also supplies power to hydraulic shift cylinders of the automatic shifting mechanism. Also, iluid is supplied through the open automatic driving control valve to the iluid shift mechanism control valve to actuate the shifting mechanism and also to cause the clutch to move into engaged position. Thus the torque is transmitted from the engine to the driving wheels of the ve- With the acceleration of the impeller in the fluid drive unit the fluid is projected outwardly by centrifugal force through the impeller blades into the buckets of the turbine wheel to effect a high degree of torque multiplication. As the turbine wheel picks up speed so that the relative slip between turbine and impeller is decreased, the torque gradually diminishes until the turbine is rotating at its maximum speed for the given load conditions. Thus the :duid coupling unit serves as a fluid transmission in starting of the vehicle and in climbing hills or overcoming other running loads.

When the accelerator is released, opening switch 252 and thereby de-energizing the solenoid 186, the spring biased armature 187 moves outwardly, rotating the actuating shaft 184 and connected valve member V into closed position as shown in Figs. 18 and 19. This cuts off the iluid supply channel 175 from the channel 215 and opens the channel 175 to the exhaust valve 209 to return the fluid to the sump. With the pump discharge by-passed through valve 209 to the sump, fluid pressure is no longer maintained to the valve 178 in the conduit to the iluid coupling casing. In consequence, the pressure within the casing drops immediately with the leakage of a very slight amount of the hydraulic luid permitted between bushing 74 and shaft 65, and with the pressure dropA the coupling effect decreases thereby conducing to the eliminationof drag between driving and driven elements at idling speeds. This result is of utility when the clutch G is not used in conjunction with couplings of the type disclosed.

Since channel 215 is now switched by valve member V to the lightly loaded relief valve 212, the pressure in the automatic channel system and the automatic shift control line is immediately released allowing the clutch to disengage and the automatic shift valve to move into inactive position, the displaced fluid discharging through valve 212 to the uid pan. The valve 212 then closes to keep the channels lled with hydraulic liuid and to prevent access of air to the duid passages.

I claim:

l. A rotary fluid coupling comprising a casing mounted for rotation by a prime mover; a driven shaft co-axial to said casing; means mounting said shaft to said casing for rotation relative thereto; a fluid impeller element including a plurality of axially extended impeller blades carried by an end wall of said casing, a turbine element Within said casing including a disk portion carried by said driven shaft, an annular rim flange extending from said disk portion in radially spaced relation to the ends of said impeller blades and a plurality of turbine blades extending axially from said disk, each turbine blade having a bucket portion secured to said rim flange and a iluid return portion secured to said disk portion extending generally radially from said bucket, said bucket portion having a free edge thereof directed rearwardly relative to the direction of rotation; each said impeller blade having outer and lateral free edge portions shaped complementarily to adjacent turbine blade portions and including a generally radially extending body, a iluid shifting vane portion extending forwardly and laterally from the inner end portion of said body at a position radially inward of the inner end of the uid return portion of said turbine blades, and a forwardly turned edge fold formed along the inner end of said body, around said vane portion and along the lateral free edge of the body outward of said vane portion.

2. A rotary iluid coupling comprising a casing mounted for rotation by a motor; a driven shaft co-axial to said casing; means mounting said shaft to said casing for rotation relative thereto; a iluid impeller element including a plurality of impeller blades carried by an end wall within said casing; a turbine element within said casing including a disc portion carried by said driven shaft, an annular rim flange extending from said disc portion in radially spaced relation to and beyond the ends of said impeller blades and a plurality of turbine blades extending axially from said disc, each turbine blade having a bucket portion secured to said rim flange and a fluid return portion secured to said disc portion extending generally radially from said bucket, said bucket portion having a free edge thereof and said iluid return portion having lateral free edge thereof turned rearwardly relative to the direction of rotation; each said impeller blade being shaped complementarily to adjacent turbine blade portions and including a body having the outward portion thereof curved forwardly relative to the direction of rotation to direct fluid into said turbine buckets, a iluid shifting vane portion extending forwardly and laterally from the inner end portion of said body at a position radially inward of the inner end of the lluid return portion of said turbine blades, and a forwardly turned edge fold formed along the inner end of said body, around said vane portion and along the lateral free edge of the body outward of said vane portion.

3. A rotary iluid coupling as described in claim 2 wherein the impeller and turbine blades are provided with sinuous intertting adjacent free edge portions.

4. A rotary fluid coupling as described in claim 2 wherein the bucket portions of said turbine blades are disposed obliquely to the axis of rotation and the outer ends of the fluid impeller blades are curved laterally to direct fluid into said bucket portions; t

5. A rotary iluid couplingv as ydescribed in claim 2 including a second iluid impeller element carried by the casing end wall opposite to the first said casing end wall and a corresponding second turbine element carried by said driven shaft.

6. A rotary iluid coupling as described in claim 2 wherein said driven shaft comprises a sleeve shaft and said means mounting said driven shaft to said casing comprises a second driven shaft extending through and rotatable relative to said sleeve shaft and journal means 11 mounting the second shaft to the casing for rotationV relative thereto, said coupling including a second uid. impeller element carried by the rst said driven shaft and a second turbine element corresponding thereto carried by said second driven shaft, whereby the secondV shaft is indirectly driven by the rst said driven shaft'.

7. A rotary fluid coupling comprising a fluid impeller element, a turbine element driven by fluid from said impeller element, a casing inclosing said elements; said impeller element having a generally radially extending bodyv portion and a plurality of blades extending axially from and disposed generally radially on saidy bodyL portion, each said impeller blade having a fluid shifting vane portion extending laterally and forwardly in the direction of rotation from the inner end portion thereof, an Youter portion curved forwardly in the direction of rotation and a forwardly turned flange extending inward to said vane portion, said llange being continuous with a forward edge fold formed along the edges of said vane portion and along the inner end of the impeller blade; and, said turbine element having a generally radially extending body portion, a peripheral ange on said body portion extending towards the impeller element in radially spaced relation to and enclosing the ends of said inipeller blades, and a plurality of turbine blades each havinga rearwardly open bucket portion on said peripheral flange and a lluid return portion on the turbine element body portion extending radially inward from said bucket portion towards said vane portions, the free edge of said bucket portion and the lateral free edge of said return portion on said turbine blade being turned rearwardly to forni a continuous channel whereby iluid projected into said bucket. portion is returned radially inwardly to the locus of said vane portions.

8., In combination a rotary fluid coupling as described in claim 2, a fixed housing for enclosing said casing, said housing providing a sump for hydraulic fluid, a hydraulic lluid pump mounted within said housing to draw iluid from said sump, means providing a driving gear conneetion between said casing and said pump, conduit means from the outlet of said pump opening to the interior Aof said coupling through the said driven shaft thereof, and pressure limiting valve means in said conduit toY limit the pressure within the casing of said coupling, said casing being provided with means adjacent to the center ofV an end wall allowing controlled leakage of fluid under pressure, by-pass valve means connecting the outlet of said pump to said sump, solenoid valve actuating means to close said bypass valve means, said actuating means being biased to move said bypass valve to` aY normally open position when the solenoid thereof is unenergized, a solenoid energizing circuit, motor speed control means, and a solenoid control switch in said cir-Y cuit linked to and operable by said control means to closed position upon setting of the control means for acceleration of the motor above a selected idling speed', whereby said pump discharge is by-passed to the` sump when the motor controller is set to idle speed condition.

`9. A rotary fluid coupling unit comprising a casingV enclosing a fluid working space for a body' of hydraulic.Y

fluid, said casing being mounted for rotation by a prime mover; a set of tluid impeller blades carried by an end. wall of said casing and extending axially therefrom; a driven shaft extending through said casing; journalA means mounting said shaft to saidV casing for rotation relative thereto; a turbine wheel within said casing securedr to said driven shaft including, a substantially radial disc portion and an annular rim flange thereon extending towardsA said endY wall outside the ends of said. impeller blades, and a set of turbine blades secured toV said flange and said disc portion with the` f ree edges 5 fold formed on the inner 12 from the inner end of said body beyond the inner ends of said turbine blades,- and a forwardly turned flange formed along the free edge of s aid impeller blade bodyV outward of said vane portion; a forwardly directed edgey edge ofV said bodyk portion. and on the edge of said vane portion merging into saidr for- Wardly turned flange;V and' said turbine blades each including a bucket portion secured within said rim flange having an inner edge turned oppositely to the direction` 10 of rotation and a lluid return portion extending radially inward from said bucket portion, said uid return portion having an edge ange joined to the turned inner edge of said bucket to providev a channel to conduct iluidy radially` inward from said bucket.

l0. A rotary uid coupling enclosing a fluid working4 space 't comprising a casing for a body of hydraulic fluid, said casing being mountedvfor rotation by a prime mover; a set of fluid impeller blades carried by an end wall of said casing. and extending axially therefrom; a

2Q driven shaft extending through said casing; journalrmeans mounting said shaft to said casing for rotation. relativeV thereto; a turbineV wheel'. within said casing secured to.

said driven shaft including a substantially radial disc Y portion and an annular rim flange thereon extending, to-

25. wards said end wall outside the ends of said impeller 3()V ly extending body w'th the outer; portion, thereof curvedV 35,- tlange formed along blades, and a set of turbine bladesV secured to said flange and said disc portion with; thefree edges thereof in close rotational proximity to theV adjacent impeller blades; said impeller blades eachrincluding aV substantially radialforwardly in the direction of rotation; a vaneV portionextending forwardly in the direction of rotation and laterally from the inner end of said body beyond they inner ends of said turbine blades, anda forwardly turned the free edge of said impeller blade body outward of saidI vane portion; a: forwardly directed edge fold formed on the inner; edge of said body portion and on theedges of said vane portion merging into said forwardly turned flange; and. said turbine blades each 40including a bucket. portion secured Within said rim Bange thereof in` close rotational proximity to the adjacent-iinpeller blades; said'impeller blades each includingasub'- stantially radially extendingV body, a vane portion; extending forwardly inthe direction of rotation and laterallyF having an inner edge turned oppositely to the direction of rotation and a iluid return portion extending radially inward from said bucket portion, said iluid return por tion having an edge;ilango joined to the turned inner edge of said bucket to providel a channel'. to conduct fluid. radially inward from said bucket.

1l. A rotary fluid' Coupling comprising aV rotary nid Y impeller element;Y a turbine element. driven through hydraulicr fluid by said impeller element; and a Ycasing Y enclosingV said elements; said impeller element comprising..

va generally radially extending bodyl poitionV and a plural-.f

ity of impeller bladesextending axially from and disposedV ,i each, said im. formed of sheet metal and` having a. 5 vblade body, an edge, flange. formed lengthwise on the;

generallyradially on said body portion;

peller blade being blade body-for attachment of .the blade. lto Ysaid impeller body portion a fluid shifting .vane portion extending-4 laterally and forwardly in the direction of rotation fromy the inner end of the blade body, a second edge ange formed at a right angle to the blade body' and extending outwardly from said vane portion, said angebeing,

directed forwardly relative to the direction of rotation, and a forwardly directed edge fold formedl on the inner edge of.Y the blade body and .on the edges of said vane 5 portion, said edge fold being joined to said second edge flange whereby the impellerbhde forced; said turbine element comprising a generally` radially extending turbine bodyf'portion, a ri'irrflange" thereon extending axially beyond the 'outer ends of said impeller blades; and azpim'alityf` ofV turbine; blades; each turbine blade beingformed of sheet metalv andA comprising a bucket portion secured tosaid* rim flange, a fluid Y portioir secured to said turbine body portion extending radially inward from. said; bucketporton, an ed'ge'ange 7 d onthe. bucket and fluid'l return portions for attachmenti ofy is structurally# reinthe turbine blade to the turbine body portion, a rearwardly directed edge fold formed along the free edge of said bucket, and an edge ange formed along the inwardly extending free edge of the fluid return directed rearwardly at right angles thereto, said edge fold of the bucket and said edge flange being joined for structural reinforcement of the turbine blade and to provide a continuous channel for fluid flow from said bucket radially inward to the locus of said uid shifting vane portions.

12. A rotary fluid coupling as described in claim 11 wherein the outer portion of each said impeller blade is curved forwardly in the direction of rotation.

13. A rotary fluid coupling as described in claim 11 wherein the free edge of each impeller blade outward of said vane and the corresponding free edge of each turbine blade are provided with complementary sinuous edge formations.

14. A rotary uid coupling as described in claim 11 wherein: the bucket portion of each turbine blade and the outer edge of each impeller blade are disposed obliquely to the axis of rotation; the inner and outer ends of the edge of each impeller blade which is secured to the said projector body portion are curved toward the turbine element; and the impeller body has inner and outer circumferential formations shaped to correspond to the shape of the impeller blades.

15. A rotary uid coupling as described in claim 11 wherein the said bucket portion of each turbine blade is disposed parallel to the axis of rotation.

16. A rotary fluid coupling as described in claim 11 wherein the said bucket portion of each turbine blade is disposed parallel to the axis of rotation, and wherein the said rim ange of the turbine element is provided with a circumferential flange extending inwardly and closing the spaces between the ends of adjacent turbine buckets.

17. A rotary fluid coupling device comprising a turbine element having a disk body portion with an axially extending rim ange, a plurality of turbine blades, each having a bucket portion and a radial iluid return portion affixed respectively to said rim flange and body portion; a rotary fluid impeller element having a disk body portion and a plurality of impeller blades aixed thereon, said impeller element being disposed within said turbine element, and each said impeller blade having at its inner end a fluid shifting vane portion extending laterally and disposed inward of the end of the uid return portion of an adjacent turbine blade; said impeller and turbine blades having complementary free edge shapes, the free edges thereof being flanged for structural strength and to provide a radial outward and inward ow channel between adjacent impeller blades and turbine blades respectively.

18. For a fluid operated transmission including a motor driven rotary turbine type fluid coupling having a coupling output shaft, a hydraulically operated clutch unit between the said coupling output shaft and the transmission input shaft, a transmission housing providing a uid sump, and a pump within said housing drawing uid from said sump: a transmission control system comprising first fluid conduit means from the outlet of said pump opening through said coupling output shaft to supply fluid to the interior of said coupling; second fluid conduit means from the outlet of said pump opening through said coupling output shaft to said hydraulically operated clutch unit to supply fluid pressure for engaging said clutch; spring closed clutch exhaust relief and pump outlet relief valves opening to said sump; a solenoidally operated rotary valve normally biased to closed position provided with port and channel systems adapted when the rotary valve is in closed position to connect the pump outlet to the pump outlet relief valve and the second conduit means to the clutch relief valve, and adapted when in open position to connect the pump outlet to said second conduit means and to block the pump outlet from said pump outlet relief valve; motor control means including a switch closed when said motor control means is set for a motor speed above a chosen idling speed; and a valve solenoid actuating circuit including said switch and the solenoid of said valve, whereby said rotary valve is moved to open position permitting said pump to apply uid pressure to said coupling and to said clutch when the motor control means is above said idling speed setting and biased to said closed position to release uid pressure from said clutch and from said pump outlet when said motor control means is at idling speed setting.

References Cited in the file of this patent UNITED STATES PATENTS 2,301,957 Lang Nov. 17, 1942 2,351,483 Carnagua June 13, 1944 2,393,859 Jandasek Jan. 29, 1946 2,407,289 La Brie Sept. 10, 1946 2,466,616 Shults Apr. 5, 1949 2,529,929 Foster Nov. 14, 1950 2,569,087 Alexandreseu Sept. 25, 1951 

